brcmfmac: fix NULL pointer access in brcmf_fweh_detach()

brcmf_fweh_detach can be called while ifp is already NULL, due to
init error. Fix NULL pointer access by checking ifp.

Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/fweh.c b/drivers/net/wireless/brcm80211/brcmfmac/fweh.c
index e1521afe6522..283acee1798b 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/fweh.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/fweh.c
@@ -374,11 +374,13 @@ void brcmf_fweh_detach(struct brcmf_pub *drvr)
         struct brcmf_if *ifp = drvr->iflist[0];
         s8 eventmask[BRCMF_EVENTING_MASK_LEN];
 
-        /* clear all events */
-        memset(eventmask, 0, BRCMF_EVENTING_MASK_LEN);
-        (void)brcmf_fil_iovar_data_set(ifp, "event_msgs",
-                                       eventmask, BRCMF_EVENTING_MASK_LEN);
-
+        if (ifp) {
+                /* clear all events */
+                memset(eventmask, 0, BRCMF_EVENTING_MASK_LEN);
+                (void)brcmf_fil_iovar_data_set(ifp, "event_msgs",
+                                               eventmask,
+                                               BRCMF_EVENTING_MASK_LEN);
+        }
         /* cancel the worker */
         cancel_work_sync(&fweh->event_work);
         WARN_ON(!list_empty(&fweh->event_q));